Piston ring



AP'IZ, 1946` v. F. ZAHODIKIN l 2,397,636

PISTON RING Filed Dec. l5', 1939 AT FQBNEYS UNITED i As'rl '.rr.s

`zeewier;

PATENT oFFlcE This invention relates to improvements in o il rings of the type adapted to be used in pistons.l

The improved ring of this invention is of par- Vticular value foruse as an oil ring forthe pistons of internal combustion engines but is not limited -to this use. It is capable of use. with the same S-advantages, as theI oil ring for the pistons of pumps, steam engines or any installation where' f itis necessary to prevent the escape of oil along `:acylinderwal1pastapiston. v V

It has been one of the objects of the vpresentv inventor to provide an oil ring for pistons which is adapted to the above uses and which will readily and easily conform to any irregularity in the contour of a cylinder and will, inthis respect, be of great value for use in' worn'cyli n-` ders. In other words the general purpose` has been to provide an oil flow control ring which will conform to 4localized irregularities or distor-I tions as well as to general irregularities in the contour of the cylinder wall.

'It has been a further object of the present. inventor to provide a piston ring which can be made, preferably, from a single strip of metal 4 275 structure of the ring after it has been punched in an extremely simple manner by forming the basic structure of the complete ring in a single punch press operation whereupon .the ringfiscompleted by bendingA operations performed'on this basic structure. The present application is directed to the article, the method being disclosed and clalmedin an applicationcopending herev with,now Patent No.2;339,538.

It has been afurther object ofthe present inventor to provide a ring formed froma flat strip of metal by punching and bending which provides a maximum 'amount of oil clearance pas- A sageway between the top and bottom walls of -the ring and through a back wall thereof. vZiurthermore it has been his object to construct and arrange the metal of the dat strip so that the ring consists oik a series of box-like segments opening `completely toward the cylinder wall and toward and from each other as compression and expansion occur. Thus a ring is provided having the gap, whichnormally permits expansion and contraction; arranged in'minute divisions around the entire circumference of the ring.

One embodiment' ofthe invention may consist of a singlestrip oi.' metal bent to provide box-like segments open tothe side yfacing the (c1. coef-i4) cylinder wall and having a perforated back'wall. Thus lthese sections appear U-shapedin radial cross section. 'I'he sections are integrally connected by spring loops, which loops are disposed betweenthe -top andbottom walls offthe ring thereby forming spacers and supports across which`the walls may slide as the loopsfilex. It

will be seen that the ring is iirmly braced against 'pressures from above and below and is integrally connected at the back so as to prevent buckling "of the top and bottom Walls when the ring is compressed'to the point of closing the minute clearances. l

.Other advantages of the invention will be more fully apparent from the description o f the drawinginwhich: p

Figure 1 is a perspectiveview showing the completed ring ready for installation in the piston and cylinder.

Figure 2 is a side view of the piston ring shown in Figure 1.

Figure 3 is a fragmentary top plan view of the Figure 4 is a plan view of a portion of the basic from the flat strip of metal.

Figure 5 is a plan view ofthe strip of Figure 4 showing the ring partially completedwith the i spring loops constituted by bending alternate "0- portions or the stripinto loops.

Figure 6 is van edge view of Figure 5 more clearly illustrating the loops.

.Figure 'l lis a view of the strip taken in the same direction as Figure 4, but showing portions 88 .of the strip bent into positionto form the top and bottom walls of the ring. Figure 8 is a plan view of Figure '1 rfurther showing the series of bent portions constituting the top and bottom walls.

v Figure 9 is a plan viewof the strip as it is being `bent into circular. form by pressing the sections together with their adjacent edges radially disposed. Referring to the drawing: r

A ilat strip of metal, l0,- is punched to provide the basic ring structure shown in Figure 4. This strip of metal is o'f'a length suiiicient for forming a single ring when all of the folding and bending operations are completed.

Referring to Figure 4, the punching operation provides a number of sections, ILpQnnectedby loop sections, l2. Each of the sect1 ,Ems-S cludes a back panel portion, I3, and top and bottom panels Il, Il. In the punch press operation a large oil clearance opening l5 is punched centrally in the back panel I3 of each section. The end edges I8 of the top and bottom panels are inclined for the reason that later on in the Iformation adjacent edges of adjacent sections are to be disposed on radial lines (Figure 9).

In the next operation the connecting portions I2 are looped as shown in Figure 6. These loops I1 flexibly connect the sections II. Obviously these sections will then be closer together.

In the next operation the top and bottom panels It, Il are bent down upon the loops by means of which they are slidahly supported. yThe loops are formed with relatively large bights' so that the top and bottom panels overhang the loops (Figure 8). Thereafter the sections are pressed closer together accentuating the looped condition of the portions I2 and, as shown in Fig-V ure 9, arranging the edges I6 on radial lines. 'Ihis completes the ring except for heat treating and grinding. i

The steel preferably used in the fabrication of this ring has the following approximate analysis: carbon, .45to .55; manganese, .60 to .90; chrome, .80 to 1.10; and vanadium, .15 to .18. This metal is sumciently ductile'before heat treatment to permit the punch press and bending operations used in the formation of the ring from a single strip of metal.

When the ring is completely formed' and set it should be properly treated to provide a ring of the maximum hardness and spring tension. For this purpose it should be heated to approximately 1450 to 1500 degrees Fahrenheit, then quenched in oil and thereafter drawn to reduce brlttleness and to obtain the desired hardness.

This is accomplished by heating to a tempera-V ture of from 600 to 800 degrees Fahrenheit. After this operation the outer periphery of the ring may be ground to provide a ring of the size desired and one having a fine finish.

This ring generates circumferential pressure through the connecting loop portions I1. These loop portions connect the back panels of the re-v spective sections and thus the pressure is exerted through these panels. The tension which the ring usually exerts on thel cylinder wall in which the ring is adapted to reciprocate will be easily controlled by initial increase or decrease in the portions to the back walls, and not to the top and bottom walls. These walls are merely carried by the back walls and supported by the loops.

The portions taking the strains of compressive and expansive forces are the circumferentially disposed back walls and they cannot buckle due to the angular bracing afforded by the top and bottom walls.

In punching the blank (Figure 4) the notches 2| are cut into the back panel on the line of the loop strips I2. Thus when the loops are formed (Figure -8) the loops begin inside the line of the upper and lower panels I l, I 4 and are therefore spaced apart at least the width of the spaces It at their attached ends 22.

Also it will be noted that the ring may be split as for example at 23 for 'convenience in assembling it onthe piston. v

Having described my invention, I claim:

l. A iiexible piston ring fabricated from a strip of resilient sheet material and consisting of a series of circumferentially arranged bent ond folded sections, U-shaped 'in radial cross section and each providing an' open front and a perforated back wall member, and spring loops connecting corresponding wall members of said sections.

2. A nexib: piston ring fabricatedV from a. strip of resilient sheet steel and consisting of top and bottom wall sections joined by back wall sections and spring loops connecting said back wall sections, said spring loops disposed parallel with the axis of the ring and between the top and bottom 4. A flexible piston ring formed lfron'lsheet metal, said ring including a series of U-shaped sections the arms of which constitute the top and bottom walls of the ring and, loop sections disposed parallel to the axis of the ring, said loop sectionshaving theirv inner ends formed integrally with the side edges of the base of the U-shaped width ofthe spaces I8 between the sections. l.

Thus the completed ring may be said to consist of box-like sections I9 interconnected by the loops I'I. The substantially continuous vground outer i edges 20 engage the cylinder wall. 'I'he ends of these box-like portions on the outer periphery are entirely open for receiving the oil. The back Vwalls include the large clearance openings I5 which permit rapid return of the oil to the back of the ring. vThe-oil clearance passages are thus quite large and there is no chance of clogging because of carbon deposit. The looped portions makeup the sides of the box-like sections andy sectionsy and their looped ends extended outwardly and laterally between the adjacent U-shaped sections whereby the top and bottom walls may slide 'on the upper and lower edges of'- the loop sections as the ringcompresses or expands.

5. A iiexiblepiston ring formed from a strip of resilient sheet material 'and consisting of a series of the boxmlike structures in any wayfjTheY sections constitutedby these walls are 'rigid and nonyieiding. ,The top and bottom walls cannot buckle or bend since they are unitarily attached along the upper` and lower edges of the back wam. The forces exerted during' the working movements of the ring are conveyed by the loop of circumferentially arranged sections, U-shape in radial cross section and providing open fronts and perforated back walls, and spring loops connecting said sections, said spring loops extending radially betweenthe upper and lower walls-of the U-shaped sections and terminating short of the Vouter periphery of the ring.

nections for the first named portions disposed between the arms of the first `named portions.

` 7. A piston' ring formed from a strip of spring steel and providinga continuous length having radially outwardly' 'projected loops formed therein and, outward extensions from the upper and lower edges of the strip intermediate the loops and constituting the top and bottom walls oi' the ring 8. A piston ring comprising a series of substantially -rectangular enclosures arranged circumferentially, the outer peripheral and inner peripheral ends of the enclosures providing for the flow of oil through the enclosures'and, spring means connecting said enclosures and constituting the side walls thereof.

v 9. A flexible piston ring formed from sheet metal, said ring including a series of U-shaped sections the arms of which constitute the top and bottom walls of the ring and, looped sections disposed parallel to the axis of the ring, said looped sections having their inner ends formed integrally with the side edges of the base of the U- shaped sections, and their looped ends extended outwardly, and said-looped ends adapted to lie between adjacent arms of the U- shaped sections whereby the top and bottom walls of adjacent U- shaped sections may slide on the upper and lower edgesl of the loop as the ring compresses or expands.

10. itself-expanding sheet metal piston ring comprising a central portion having a successive elements.

11. A se1fexpsnding piston ring formed of sheet metal comprising a central corrugated portion extending around through'the entire c ircumference of the piston ring and having corrugations thereindisposedin a generally radial directlon (as distinguished from a generally axial direction) and a multiplicity of cylinder-contacting elements flanking said central corrugated portion and extending throughout the circumference of the ring to form a pair of spaced sectional annular cylinder-contacting ribs, said cylinder-contacting elements being disposed outwardly from said central corrugated portion and adjacent cylindercontacting elements being so arranged in close proximity to each other as to form a more or less continuous cylinder-contacting rib; said corrugations tending to expand the piston ring circumferentially and also radially outwardly when the ring is confined to the cylinder diameter.

12. A self-expanding piston ring formed of sheet metal comprising' a central corrugated portion extending around through the entire circumference of the piston ring and having corrugations formed outwardly thereof in a generally radialdirection (as distinguished from a, Senerally axial direction) and a multiplicity of cylluder-contacting elements flanking said central corrugated portion and extending throughout the circumference of the ring to form a pair of spaced sectional annular cylinder-contacting ribs, said cylinder-contacting elements being disposed outwardly from said-central corrugated portion and adjacent cylinder-contacting elements being so arranged in close'proximity to each other as to forma more or less continuous cylinder-contacting rib, said corrugations tending to expand the piston ring circumferentially and also radially outwardly when the ring is coniined to the cylinder diameter. said corrugationsjserving also to support said cylinder-contacting elements axially.

13. As an article o1' manufacture, a piston ring comprising a strip of resilient sheet material formed at opposite edges with segments extending therefrom, said material being folded transversely of the strip to comprise an annular body in which the folds of material are radial of thering and at 'right angles to the segments, said segments formed to comprise circumferential 'sealing surfaces for, the ring.

VICTOR F. ZAHODIAKIN. 

